Re: [PATCH v3 4/4] Update the C FE routine "add_flexible_array_elts_to_size" C++ FE routine "layout_var_decl" to handle the cases when the DECL is union.
On Apr 30, 2024, at 15:29, Jason Merrill wrote:
On 4/30/24 07:58, Qing Zhao wrote:
Add testing cases to test the _bos for flexible array members in unions
or alone in structures.
gcc/c/ChangeLog:
* c-decl.cc (add_flexible_array_elts_to_size): Handle the cases
when the DECL is union.
gcc/cp/ChangeLog:
* decl.cc (layout_var_decl): Handle the cases when the DECL is
union with a flexible array member initializer.
gcc/testsuite/ChangeLog:
* c-c++-common/fam-in-union-alone-in-struct-bos-1.c: New test.
* c-c++-common/fam-in-union-alone-in-struct-bos.c: New test.
---
gcc/c/c-decl.cc | 32 +++--
gcc/cp/decl.cc| 33 --
.../fam-in-union-alone-in-struct-bos-1.c | 66 +++
.../fam-in-union-alone-in-struct-bos.c| 45 +
4 files changed, 162 insertions(+), 14 deletions(-)
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos-1.c
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos.c
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 947f3cd589eb..59302c5cfb1f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -5337,9 +5337,9 @@ zero_length_array_type_p (const_tree type)
}
/* INIT is a constructor that forms DECL's initializer. If the final
- element initializes a flexible array field, add the size of that
- initializer to DECL's size. */
-
+ element initializes a flexible array field, adjust the size of the
+ DECL with the initializer based on whether the DECL is a union or
+ a structure. */
static void
add_flexible_array_elts_to_size (tree decl, tree init)
{
@@ -5348,15 +5348,33 @@ add_flexible_array_elts_to_size (tree decl, tree init)
if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
return;
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
In both C and C++ front-ends, I don't see any reason for this variable to be
declared outside the if, since it's only used inside it.
It's not clear to me that it's needed at all since it's only used once, but if
you prefer to have it, please move it inside the if.
Okay, will do that.
thanks.
Qing
+
elt = CONSTRUCTOR_ELTS (init)->last ().value;
type = TREE_TYPE (elt);
if (flexible_array_member_type_p (type))
{
complete_array_type (, elt, false);
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type));
+ /* For a structure, add the size of the initializer to the DECL's
+ size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
+ /* For a union, the DECL's size is the maximum of the current size
+ and the size of the initializer. */
+ else
+ {
+ DECL_SIZE (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
}
}
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 9a91c6f80da1..0ea3ef165b66 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -6555,8 +6555,9 @@ layout_var_decl (tree decl)
}
}
- /* If the final element initializes a flexible array field, add the size of
- that initializer to DECL's size. */
+ /* If the final element initializes a flexible array field, adjust
+ the size of the DECL with the initializer based on whether the
+ DECL is a union or a structure. */
if (type != error_mark_node
&& DECL_INITIAL (decl)
&& TREE_CODE (DECL_INITIAL (decl)) == CONSTRUCTOR
@@ -6568,6 +6569,7 @@ layout_var_decl (tree decl)
&& tree_int_cst_equal (DECL_SIZE (decl), TYPE_SIZE (type)))
{
constructor_elt = CONSTRUCTOR_ELTS (DECL_INITIAL (decl))->last ();
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
if (elt.index)
{
tree itype = TREE_TYPE (elt.index);
@@ -6577,11 +6579,28 @@ layout_var_decl (tree decl)
&& TREE_CODE (vtype) == ARRAY_TYPE
&& COMPLETE_TYPE_P (vtype))
{
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (vtype));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
- TYPE_SIZE_UNIT (vtype));
+ /* For a structure, add the size of the initializer to the DECL's
+ size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE (decl),
+ TYPE_SIZE (vtype));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (vtype));
+ }
+ /* a union, the DECL's size is the maximum of the current size
+ and the size of the initializer. */
+ else
+ {
+ DECL_SIZE (decl)
+
Re: [PATCH v3 4/4] Update the C FE routine "add_flexible_array_elts_to_size" C++ FE routine "layout_var_decl" to handle the cases when the DECL is union.
On 4/30/24 07:58, Qing Zhao wrote:
Add testing cases to test the _bos for flexible array members in unions
or alone in structures.
gcc/c/ChangeLog:
* c-decl.cc (add_flexible_array_elts_to_size): Handle the cases
when the DECL is union.
gcc/cp/ChangeLog:
* decl.cc (layout_var_decl): Handle the cases when the DECL is
union with a flexible array member initializer.
gcc/testsuite/ChangeLog:
* c-c++-common/fam-in-union-alone-in-struct-bos-1.c: New test.
* c-c++-common/fam-in-union-alone-in-struct-bos.c: New test.
---
gcc/c/c-decl.cc | 32 +++--
gcc/cp/decl.cc| 33 --
.../fam-in-union-alone-in-struct-bos-1.c | 66 +++
.../fam-in-union-alone-in-struct-bos.c| 45 +
4 files changed, 162 insertions(+), 14 deletions(-)
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos-1.c
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos.c
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 947f3cd589eb..59302c5cfb1f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -5337,9 +5337,9 @@ zero_length_array_type_p (const_tree type)
}
/* INIT is a constructor that forms DECL's initializer. If the final
- element initializes a flexible array field, add the size of that
- initializer to DECL's size. */
-
+ element initializes a flexible array field, adjust the size of the
+ DECL with the initializer based on whether the DECL is a union or
+ a structure. */
static void
add_flexible_array_elts_to_size (tree decl, tree init)
{
@@ -5348,15 +5348,33 @@ add_flexible_array_elts_to_size (tree decl, tree init)
if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
return;
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
In both C and C++ front-ends, I don't see any reason for this variable
to be declared outside the if, since it's only used inside it.
It's not clear to me that it's needed at all since it's only used once,
but if you prefer to have it, please move it inside the if.
+
elt = CONSTRUCTOR_ELTS (init)->last ().value;
type = TREE_TYPE (elt);
if (flexible_array_member_type_p (type))
{
complete_array_type (, elt, false);
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type));
+ /* For a structure, add the size of the initializer to the DECL's
+size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
+ /* For a union, the DECL's size is the maximum of the current size
+and the size of the initializer. */
+ else
+ {
+ DECL_SIZE (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
}
}
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 9a91c6f80da1..0ea3ef165b66 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -6555,8 +6555,9 @@ layout_var_decl (tree decl)
}
}
- /* If the final element initializes a flexible array field, add the size of
- that initializer to DECL's size. */
+ /* If the final element initializes a flexible array field, adjust
+ the size of the DECL with the initializer based on whether the
+ DECL is a union or a structure. */
if (type != error_mark_node
&& DECL_INITIAL (decl)
&& TREE_CODE (DECL_INITIAL (decl)) == CONSTRUCTOR
@@ -6568,6 +6569,7 @@ layout_var_decl (tree decl)
&& tree_int_cst_equal (DECL_SIZE (decl), TYPE_SIZE (type)))
{
constructor_elt = CONSTRUCTOR_ELTS (DECL_INITIAL (decl))->last ();
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
if (elt.index)
{
tree itype = TREE_TYPE (elt.index);
@@ -6577,11 +6579,28 @@ layout_var_decl (tree decl)
&& TREE_CODE (vtype) == ARRAY_TYPE
&& COMPLETE_TYPE_P (vtype))
{
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (vtype));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
- TYPE_SIZE_UNIT (vtype));
+ /* For a structure, add the size of the initializer to the DECL's
+size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop
[PATCH v3 4/4] Update the C FE routine "add_flexible_array_elts_to_size" C++ FE routine "layout_var_decl" to handle the cases when the DECL is union.
Add testing cases to test the _bos for flexible array members in unions
or alone in structures.
gcc/c/ChangeLog:
* c-decl.cc (add_flexible_array_elts_to_size): Handle the cases
when the DECL is union.
gcc/cp/ChangeLog:
* decl.cc (layout_var_decl): Handle the cases when the DECL is
union with a flexible array member initializer.
gcc/testsuite/ChangeLog:
* c-c++-common/fam-in-union-alone-in-struct-bos-1.c: New test.
* c-c++-common/fam-in-union-alone-in-struct-bos.c: New test.
---
gcc/c/c-decl.cc | 32 +++--
gcc/cp/decl.cc| 33 --
.../fam-in-union-alone-in-struct-bos-1.c | 66 +++
.../fam-in-union-alone-in-struct-bos.c| 45 +
4 files changed, 162 insertions(+), 14 deletions(-)
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos-1.c
create mode 100644
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos.c
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 947f3cd589eb..59302c5cfb1f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -5337,9 +5337,9 @@ zero_length_array_type_p (const_tree type)
}
/* INIT is a constructor that forms DECL's initializer. If the final
- element initializes a flexible array field, add the size of that
- initializer to DECL's size. */
-
+ element initializes a flexible array field, adjust the size of the
+ DECL with the initializer based on whether the DECL is a union or
+ a structure. */
static void
add_flexible_array_elts_to_size (tree decl, tree init)
{
@@ -5348,15 +5348,33 @@ add_flexible_array_elts_to_size (tree decl, tree init)
if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
return;
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
+
elt = CONSTRUCTOR_ELTS (init)->last ().value;
type = TREE_TYPE (elt);
if (flexible_array_member_type_p (type))
{
complete_array_type (, elt, false);
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type));
+ /* For a structure, add the size of the initializer to the DECL's
+size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
+ /* For a union, the DECL's size is the maximum of the current size
+and the size of the initializer. */
+ else
+ {
+ DECL_SIZE (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (MAX_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (type));
+ }
}
}
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 9a91c6f80da1..0ea3ef165b66 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -6555,8 +6555,9 @@ layout_var_decl (tree decl)
}
}
- /* If the final element initializes a flexible array field, add the size of
- that initializer to DECL's size. */
+ /* If the final element initializes a flexible array field, adjust
+ the size of the DECL with the initializer based on whether the
+ DECL is a union or a structure. */
if (type != error_mark_node
&& DECL_INITIAL (decl)
&& TREE_CODE (DECL_INITIAL (decl)) == CONSTRUCTOR
@@ -6568,6 +6569,7 @@ layout_var_decl (tree decl)
&& tree_int_cst_equal (DECL_SIZE (decl), TYPE_SIZE (type)))
{
constructor_elt = CONSTRUCTOR_ELTS (DECL_INITIAL (decl))->last ();
+ bool is_decl_type_union = (TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
if (elt.index)
{
tree itype = TREE_TYPE (elt.index);
@@ -6577,11 +6579,28 @@ layout_var_decl (tree decl)
&& TREE_CODE (vtype) == ARRAY_TYPE
&& COMPLETE_TYPE_P (vtype))
{
- DECL_SIZE (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (vtype));
- DECL_SIZE_UNIT (decl)
- = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
- TYPE_SIZE_UNIT (vtype));
+ /* For a structure, add the size of the initializer to the DECL's
+size. */
+ if (!is_decl_type_union)
+ {
+ DECL_SIZE (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE (decl),
+ TYPE_SIZE (vtype));
+ DECL_SIZE_UNIT (decl)
+ = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
+ TYPE_SIZE_UNIT (vtype));
+ }
+ /* a union, the DECL's size is the maximum of the current size
+
